Field of the Invention
The invention relates to a method and a device for activating an element made of a shape memory alloy.
Elements made of shape memory alloys (also known as memory metal) have the known property of changing their shape when heated and reverting to the original shape when cooled.
Published, Non-Prosecuted German Patent Application DE 199 47 324 A1 discloses a changeover device of a domestic dishwasher. The valve body of which is brought into a closed position, against the force of a restoring spring, by a heated compression spring made of a shape memory alloy and is brought into an open position by the restoring spring. The compression spring made of the shape memory alloy is heated by a heating element, preferably by a positive temperature component (PTC) element. A separate control circuit is required for this purpose.
However, there are also known applications in which an element made of a shape memory alloy is heated by passing electric current through it. A separate control circuit is required for this purpose.
The previously known configurations are complicated and expensive.